Hi Andrei, well to use the Transform > Scale > Scale 2D command, you start by selecting the objects you want to scale. Then run the Scale2D command, then at the first prompt pick the origin point for the scale. The view that you pick the origin point in is significant, the x/y axes of the grid plane of that view will be used for the scaling.

Then to define the amount of scale you can either pick 2 reference points and the ratio between the distance from each of those points to the origin will be the scale factor, or you can type in a numeric scale factor like 0.5 for example will scale it by half in size in just the x and y axes and leave the z axis size alone.

If you're having difficulty with a particular model maybe you could post a 3DM file?

Thanx for replyes)
I have problem becouse I do not know that grid plane play role here. I tried in 3D view to scale cylinder that was rotated a bit. And when I tried to scale it, I get it "distorted". Thanks.